Senna leaf tea has been used for centuries, originating with the ancient Egyptians over 3,500 years ago. It was introduced to Europe during the Crusades, and has remained popular in the Western world ever since. Today, it is most frequently used as a mild laxative, and is seen in many different detoxification or weight loss herbal supplements and formulas for this reason. It grows naturally in most tropical regions in the world, and while both the leaves and seeds can be medicinal, the tea is typically made using the leaves as these produce the best results.